Storage and transportation of solid carbon dioxide



Dec. 23, 19311.l n n c. LfJ'oNEs 'r AL STORAGE AND TRANSPORTATION OF SOLID OARBON DIOXIDE Filed April e. 1929 INVENTOR @Mr/aj. @Me

ATTORNEY Patented Dec. 23, 1930 UNITED ASTATES PATENT OFFICE CHARLES L. JONES, OF PITTSBURGH, IPENNSYLVANIA, AND JOHN D. SMALL, OF DOUGLASTON, NEW YORK, ASSIGNORS T0 DRYICE EQUIPMENT CORPORATION, 'OF NEW YORK, N. Y., A CORPORATION OF DELAWARE STORAGE AND TRANSPORTATION OF SOLID CARBON DIOXIDE Application filed April 6,

storage and transportation. Such blocks are now Well known, one standard product being relatively porous, l0-inch cubes, weighing 40 pounds, made by compressing minute crystals or snow, made by jet expansion of liquid carbon dioxide; but the invention is equally applicable to cakes of other sizes and sha es, or made in other ways. y

, owevei made, vit is commercially important that the blocks conform to some selected standard of size, weight and shape and, what is equally important, that they remain as near standard as possible from the time they are made at the factory to the time they are used by the consumer.

For storage and distribution, these cakes are commonly placed in receptacles or boxes of design and material adapted for keeping the cakes well insulated from exterior heat, thick-walled balsa wood boxes being commonly employed for this purpose. Economy of box cost and weight, as well as effectiveness of protection of the solid carbon dioxide,

requires that the boxes be of relatively large size, and preferably tending toward the proportions of a cube, both factors operating to reduce the box wall area per unit volume of solid carbon dioxide within the box. Hence, a large number of cakes or cubes Vwill `be packed in a single box, and, naturally, they are piled several cakes deep, common arrangements being, say, 10 inch cubes, in three to live layers, each comprising as many cubes as `may be desired. A

N o matter how well packed and insulated'Al the blocks are peculiarly subject to evaporation losses because of their very low temperature, which is normally about 110 F. below zero when the blocks are in pure carbon dioxide gas but which may be 30 to 40 lower when the blocks are freely exposed to air. This is because any given percentage of air in the gas acts like a corresponding percentage of vacuum, accelerating evaporation and producinglow temperatures. As these temperatures are some 200 degrees below the ordinary external temperatures to which the 1929. Serial No. 353,238.

`storage bins are likely to be exposed in commercial practice, the evaporation losses may be very great. i

The present invention, however, relates more particularly to another serious cause of loss through the change of shape of the block due to selective erosion, particularly in the top layer of a stack of cakes, especially at the exposed corner of each corner cake. Many of the important uses of the cakes involve sawing them into suitable sizes and shapes, and as these sub-divided cakes should be standard as to shape, size and refrigerant value, a relatively small evaporation loss is likely to cause change of shape of the original block, which very disproportionately decreases the number of standard sub-divided cakes that can be sawed therefrom. These difficulties are more fully explained in the application of Martin, Ser. No. 235,044, but i that application minimizing evaporation and change of shape, is by enclosing the standard large cakes in paper bags so that they will be shielded from eroding air-gas currents, when stacked in the storage or shipping case.

The present invention, however, relates to an entirely distinct method of minimizing erosion which, though particularly adapted for practice in combination with the Martin bag-protected blocks, is also capable of very advantageous use vindependently of or as a substitute for said method.

When the blocks are packed or stacked in vthe insulating boxes or bins as above described, a desired amount of solid carbon dioxide can be added or substituted in such form or condition that it can be made to evaporate selectively, so as to provide protective cold gas for the blocks, thereby minimizing melting thereof and substantially preventing serious erosion effects and loss of shape,

until most if not all of the additional, proof the o-rdinary minute snowl crystals or pieces of crushed cakes. Another factor of selective melting is the location of the added material and in the referred practice of our method we prefera ly apply the snow or other finely subdivided material so as to cover the top layer of blocks, particularly at the edges and corners. One specilic but practically important feature of novelty consists in omitting the corner blocks of the top layer in each box or bin and filling the space thereof with the snow. If the stack is in a box of a kind likely to be turned wrong side-up, the corner blocks of the bottom layer may be similarly omitted, and the space filled with snow. While such protection of the top corners of the stack by selectively melting material constitutes in itself a great improvement in the art, as does also the use of a top layer without substituting the corner blocks,

we prefer to use both expedients and also to sift the snow or crushed cakes into any andv all voids around or within the stack.

As to the utility and economy of our method, it will be evident that `although a given weight of more'or less costly solid carbon dioxide must be used up in preserving the contents of the package, the selective wasting of the unformed snow before the blocks begin to waste materially, results in important economy in preserving the full commercial value of the blocks and it costs slightly less to make the finely subdivided material than it does to make lsaid blocks. Moreover, imperfect or accidentally broken blocks may be crushed and used for the purpose.

The above and other features of my invention will be more evident from the following description in connection with the accompanying drawings, in which Fig. l is a vertical section on the line 1 1, Fig. 2, showing more or less diagrammatically a stack of solid carbon dioxide blocks packed in accordance with our present invention;

gig. 2 is a section on the line 2-2, Fig. l; an

Fig. 3 is a detail showing in perspective the end of one of the blocks and in section a paper wrapper or bag that may or may not be used in connection therewith. V

In Fig. 1, the storage box or bin is shown as comprising a bottom 1, sides 2, 3 and cover 4 of insulating material. This may be balsa wood or any other known or desired material or construction adapted to retain the blocks and the carbon dioxide gas that may be sublimated therefrom.

Within the box are the parallel stacks of blocks of the solid carbon dioxide comprising lower blocks 5, 5, superposed blocks' 6, 6 and top blocks 7, 7. While it is usually not desirable to have more than three to ve vertic al layers, if the blocks are of relatively large size, the number of blocks in each layer may be as many as desired within limits. As diagrammatically indicated in Figs. 1 and 2, the blocks may be enclosed in paper as illustrated f in detail in Fig. 3, wherein the bag is shown as of a size to fairly it the block and to fold over snugly at the'top with flaps 9, which may be secured by paster 10. While this paper envelope is a decided advantage in magnifying the difference in melting rate between the blocks which are to be preserved and the additional finely subdivided carbon dioxide or snow which is an essential of our present method, it will be understood that our invention is independent of the paper wrapper and this may be and frequently is omitted.

As more or less diagrammatically indicated, the additional finely subdivided solid carbon dioxide is packed in the container, above the topmost layer, as at l1, and preferably also in the voids between the blocks and the container wall as at 12, 12. Also there may be a layer on the bottom of the container.

In view of the above noted fact that the finely subdivided carbon dioxide or snow will melt selectively until most of'it has been used up, it is frequently desirable to remove one or more of the blocks and use the space for storage of snow. An important specific feature of our invention consists in thus remov- 'ing and filling the space of the corner blocks which are most exposed to heat, particularly the corner blocks of the upper layer. This arrangement is indicated for the spaces, 5m, 5m, etc., at the corners of the upper layer of blocks. This expedient alone aords great protection against evaporative change of shape of the blocks but in most cases it is preferred to use additional snow or the like in combination with or as a substitute for the shapes of the blocks are seriously impaired.

2. The method of protecting blocks of solid carbon dioxide'which includes enclosing the same in a container and protecting the same by carbon dioxide snow.

3. The method of portecting blocks of solid carbon dioxide which includes enclosing the same in a container and protecting the same by solid carbon dioxide that is flnely subdivided and arranged to be at least as exposed as the blocks to atmospheric circulation and heat within the container.

4. The method of protecting blocks of solid carbon dioxide which includes enclosing the same in a container and protectin the same by solid carbon dioxide that is nely subdivided and arranged to be more exposed than the blocks to atmospheric circulation and heat within the container.

5. The method of protecting the shapes of similarly shaped solid carbon dioxide blocks, during storage and transportation, which includesV partially protecting the blocks by stacking the blocks in layers in a suitable container and further protecting the blocks by enclosing therewith and exposing to the circulatory. atmosphere iinely subdivided solid carbon dioxide. Y 6. The method of protecting the shapes of similarly shaped solid carbon dioxide blocks, during storage and transportation, which includes partially protecting the blocks by stacking the blocks in layers in a suitable container and further protecting the blocks by enclosing therewith and exposing to the circulatory atmosphere in the upper part of saidV container, inely subdivided solid carbon dioxide.

7. The method of portecting the shapes of similarly shaped solid carbon dioxide blocks, during storage and transportation, which includes partially protecting the blocks by stacking the blocks in layers in a suitable container and further protecting the blocks by enclosing therewith and exposing to the circulatory atmosphere in the upper part of said container carbon dioxide snow.

8. The method of protecting the shapes of similarly shaped solid carbon dioxide blocks, during storage and transportation, which includes partially protecting the blocks by stacking the blocks in layers in a suitable container and further protecting the blocks by enclosing therewith and exposing the circulatory atmosphere inely subdivided solid carbon dioxide distributed in the voids above the blocks and between the blocks and the container.

9. The method of protecting the shapes of similarly shaped solid carbon dioxide blocks,

during storage and transportation, which ini cludes partially protecting the blocks by stacking the blocks in layers in a suitable container and further protecting the blocks by enclosing therewith and exposing' to the circulatory atmosphere, carbon dioxide snow distributed in the voids above the blocks and between the blocks and the container.

.10. The method of protecting standardized rectangular blocks of solid carbon dioxide during storage and transportation, which includes partially protecting the blocks by stacking the blocks in regular layers in a suitable container and further protecting the blocks by enclosing therewith a quantity of iinely subdivided solidcarbon dioxide.

11. The method of protecting standardized rectangular blocks of solid carbon dioxide during storage and transportation, which includes partially protecting the blocks by stacking the blocks in regular layers in a suitable container and further protecting the blocks by enclosing therewith in the upper part of said container, a quantity of finely subdivided solid carbon dioxide.

12. The method of protecting standardized rectangular blocks of solid carbon dioxide placing the corner blocks of the upper stack.

13. The method of protecting blocks of solid carbon dioxide during storage and transportation, which includes partially protecting the blocks by enclosing each separately in a protective wrapper, stacking the protected blocks in superposed layers in a suitable container and further protecting the blocks by exposing to the circulatory atmospherev in the upper part of said container, a quantity of unprotected solid carbon dioxide.

14. The method of protecting blocks of solid carbon dioxide during storage and transportation, which includes partially pro-b tecting the blocks by enclosing each separately in a protective wrapper, stacking the protected blocks in superposed layers in a suitable container and further protecting the blocks by exposing to the circulatory atmosphere in the upper part of said container, a quantity of unprotected solid carbon dioxide replacing the corner blocks of the upper stack.

15. A storage or transportation container, layers of blocks of solid carbon dioxide stacked therein and finely subdivided solid carbon dioxide exposed to the convection currents within said container.

16. A storage or transportation container, layers of blocks of solid carbon dioxide stacked therein and iinely subdivided solid carbon dioxide arranged about the upper portion of the stack.

17. A storage or transportation container, layers of blocks of solid carbon dioxide stacked therein and finely subdivided solid carbon dioxide distributed around and in the crevices between the blocks and the container.

18. A storage or transport-ation container,

storage or transportation purposes, having therein superposed layers Vof standardized rectangular blocks of frozen carbon dioxide, in combination with means for shielding each individual block from the general con- 5 vection currents set up within the container and with a quantity of finely subdivided frozen carbon dioxide, exposed to said convection currents.

21. An insulating container adapted for storage or transportation'purposes, having therein superposed layers of blocks of frozen carbon dioxide, in combination with means for shielding each individual block from the general convection currents set up Within the container and with a quantity of unshielded frozen carbon dioxide directly exposed to said convection currents.

Signed at New. York, in the county of New York and State of New York, this 5th day of April, A. D., 1929.

CHARLES L. JONES.

JOHN D. SMALL. 

